Why did they buy return
train tickets to Luton? Why did they buy pay & display tickets for cars?
Why were there no usual shouts of 'Allah Akhbar'? Why were bombs in bags
and not on their bodies?

THE London bombers may have been duped into killing themselves so their
secrets stayed hidden.

Police and MI5 are probing if the four men were told
by their al-Qaeda controller they had time to escape after setting off timers.
Instead, the devices exploded immediately.

A security source said: "If the bombers lived
and were caught they'd probably have cracked. Would their masters have allowed
that to happen? We think not."

The evidence is compelling: The terrorists bought
return rail tickets, and pay and display car park tickets, before boarding
_ a train at Luton for London. None of the men was heard to cry "Allah
Akhbar!" - "God is great" - usually screamed by suicide bombers
as they detonate their bomb.

Their devices were in large rucksacks which could
be easily dumped instead of being strapped to their bodies. They carried
wallets containing their driving licences, bank cards and other personal
items. Suicide bombers normally strip themselves of identifying material.

Similar terror attacks against public transport in Madrid last year were
carried out by recruits who had time to escape and planned to strike again.

Bomber Hasib Hussain detonated his device at the rear of the top deck of
a No 30 bus, not in the middle of the bottom deck where most damage would
be caused.

Additionally, two of the bombers had strong personal reasons for staying
alive.

Jermaine Lindsay's partner Samantha Lewthwaite, 22, mother of his one-year-old
son, is expecting her second baby within days. Mohammed Sidique Khan's wife
Hasina, mum of a 14-month-old daughter, is also pregnant.

Our source disclosed: "The theory that they were not a suicide squad
is gathering pace. They were the weakest link.

"We think it's possible they were told that when they pressed buttons
to set off timers they'd have a short time to abandon the bombs and get
away before the blast. Instead, the bombs exploded immediately."

Another intelligence source added: "Whoever is behind this didn't want
to waste their best operatives on a suicide mission. Instead they used easily
recruited low-grade men who may have believed they'd walk away."

At least 54 people were killed in the 7/7 blasts. Khan, 30, of Dewsbury,
Shehzad Tanweer, 22, of Leeds, and Jamaican-born Lindsay, 19, of Aylesbury,
Bucks, detonated devices on the Tube at Edgware Road, Aldgate and King's
Cross.

Hussain, 18, of Leeds, blasted the bus at Tavistock Square. The Tube explosions
went off almost simultaneously. But the bus went up an hour later.

Yesterday, Hussain's family told of their horror at the teenager's involvement
in the massacre. They said in a statement: "We are devastated over
the events of the past few days. Hasib was a loving and normal young man
who gave us no concern and we are having difficulty taking this in.

"Our thoughts are with all the bereaved families. We have to live with
the loss of our son in these difficult circumstances.

"We had no knowledge of his activities and, had we done, we would have
done everything in our power to stop him. We urge anyone with information
to cooperate fully with the authorities."

Police are urgently investigating the missing 81 minutes between Hussain
arriving from Luton in London and the time his bomb went off.

His device may have malfunctioned. He may have lost his nerve. Or he may
have panicked when he discovered the Northern Line, on which he is thought
to have been due to travel, was suspended.

Officers want to discover if Hussain met anyone else who either strengthened
his faltering resolve or reset his flawed bomb.